Added examples for basic IO
Added an example of pcm_writei usage and an example of pcm_readi
usage. Both examples use a common file called 'audio.raw'.
diff --git a/examples/pcm-readi.c b/examples/pcm-readi.c
new file mode 100644
index 0000000..5b85ca6
--- /dev/null
+++ b/examples/pcm-readi.c
@@ -0,0 +1,83 @@
+#include <stdio.h>
+#include <stdlib.h>
+
+#include <tinyalsa/pcm.h>
+
+static size_t read_frames(void **frames)
+{
+ unsigned int card = 0;
+ unsigned int device = 0;
+ int flags = PCM_IN;
+
+ const struct pcm_config config = {
+ .channels = 2,
+ .rate = 48000,
+ .format = PCM_FORMAT_S32_LE,
+ .period_size = 1024,
+ .period_count = 2,
+ .start_threshold = 1024,
+ .silence_threshold = 1024 * 2,
+ .stop_threshold = 1024 * 2
+ };
+
+ struct pcm *pcm = pcm_open(card, device, flags, &config);
+ if (pcm == NULL) {
+ fprintf(stderr, "failed to allocate memory for PCM\n");
+ return EXIT_FAILURE;
+ } else if (!pcm_is_ready(pcm)){
+ pcm_close(pcm);
+ fprintf(stderr, "failed to open PCM\n");
+ return EXIT_FAILURE;
+ }
+
+ unsigned int frame_size = pcm_frames_to_bytes(pcm, 1);
+ unsigned int frames_per_sec = pcm_get_rate(pcm);
+
+ *frames = malloc(frame_size * frames_per_sec);
+ if (*frames == NULL) {
+ fprintf(stderr, "failed to allocate frames\n");
+ pcm_close(pcm);
+ return EXIT_FAILURE;
+ }
+
+ int read_count = pcm_readi(pcm, *frames, frames_per_sec);
+
+ size_t byte_count = pcm_frames_to_bytes(pcm, read_count);
+
+ pcm_close(pcm);
+
+ return byte_count;
+}
+
+static int write_file(const void *frames, size_t size)
+{
+ FILE *output_file = fopen("audio.raw", "wb");
+ if (output_file == NULL) {
+ perror("failed to open 'audio.raw' for writing");
+ return EXIT_FAILURE;
+ }
+ fwrite(frames, 1, size, output_file);
+ fclose(output_file);
+ return 0;
+}
+
+int main(void)
+{
+ void *frames;
+ size_t size;
+
+ size = read_frames(&frames);
+ if (size == 0) {
+ return EXIT_FAILURE;
+ }
+
+ if (write_file(frames, size) < 0) {
+ free(frames);
+ return EXIT_FAILURE;
+ }
+
+ free(frames);
+
+ return EXIT_SUCCESS;
+}
+